Carburetor



oct. 6, 1959 H. COANDA CARBURETOR 4 Sheets-Sheet 1 Filed Sept. 26, 1956 H. COANDA CARBURETOR Oct. 1959 4 Sheets-Sheet 2 Filed Sept. 26, 1956 H. COANDA Oct. 6, 1959 CARBURETOR Filed sept. 2e, 195e 4 Sheets-Sheet 3 United Statesv Patent O cARBUREroR Henri Coanda, AParis, France, assignor to Societe Sebac Nouvelle S.A., Lausanne, Switzerland, a company of Switzerland Application September 26, 1956, Serial No. 612,215

Claims priority, application FranceSeptember 23, '1952 16 Claims. (Cl. 261-78) This invention relates to a process for preparing carburized Ffuel-air mixtures effective to provide excellent combustion in the cylinders of internal-combustion engines and to a carburetor of novel construction. More particularly, the invention is concerned with a device which automatically insures the proper proportioning of a mixture of at least one carburant, e.g. gasoline, and one comburant, e.g. air, in the cylinders of internal-combustion engines.

It is known that it is desirable to feed the cylinders i an internal-combustion engine with a relatively cold carburized mixture which comprises very small liquid drops of fuel in suspension for the purpose of insuring the proper charging of the cylinders, and consequent efticaceous and eicient combustion. Fluids, and in particular hydrocarbons, which are generally utilized as carburants in internal-combustion engines of the explosion type, have a volume of the order of 1,000 to 2,000 times greater in the gaseous state than in the liquid state. It is consequently essentialthat, in a carburized mixture, the carburant should not be in the gaseous state but in the liquid state if one desires to assure a correct charging of the cylinders with the carburized mixture.-

In accordance with the process of this invention, there is prepared -a carburized mixture which holds in suspension small dropsl ,of` liquid (as an atomized mist or aerosol) because the extreme velocity of the lluids handled eiects atomization in the cold without gasification.

In accordance lwith one of the characteristics of the invention, there is obtained a carburized mixture containing ionized particles, the liquid particles exhibiting ionization of the same polarity, so that the particles repel each other and there is brought about an 'excellent distribution of the liquid particles in the cylinders of the'engine, thus favoring combustion.

The carburetor of the invention is of a very economical construction and is free from the complex, expensive, and Wear-prone mechanisms of carburetors heretofore known. Flow through the carburetor is easy to regulate at all times by means of simple controls and the carburetor provides a teedof fuel to the cylinders which approaches direct injection and thus assures an excellent tilling of the cylinders with a mixture of a comburant and very tine liquid particles of the carburant, the mixture being `at a relatively low temperature.

In order to` realize the maximum benefits obtainable with the carburetor of the invention, it is advantageous to provide one carburetor for each cylinder, or, atthe most, one carburetor for each two adjacent cylinders, which is economically possible owing to the greatly reduced cost of a carburetor according tothe invention. One thus decreases the distance travelled by the carburized mixture and the number of changes in direction of ilow` of the mixture caused by the successive feed of several cylinders, as compared with the case when a single carburetor feeds several cylinders, such as in conventional motor vehicle engines. However, it is to beunderstood that, without departing from the scope of the invention,

2,907,557 Patented Oct. 6, 1959 lCC ` one-can use a single carburetor constructed in accordance with the invention to feed more than two cylinders, but such an arrangement is less advantageous. There is disclosed in my co-pending application, Serial No. 377,898, filed September l, 1953 now Patent No. 2,770,501, granted November 13, 1956, a liquid atomizing device characterized by the provision, in a conduit in which a uid is caused to llow, of a blade or vane with a substantially symmetrical cross-section, which is disposed between walls only along that portion which corresponds to laminar ilow of fluid along its extrados and its intrados, a substantially triangular cavity being formed in the blade with its apex ldirected -towards the leading or upstream edge of the blade, grooves or channels being also formed in the blade for the purpose of bringing together in the above-mentioned cavity jets of the liquid or liquids to be atomized.

When one provides a blade or vane formed with a cavity or cutout and at least one channel to introduce in the cavity at least one jet of a carburant liquid, in a conduit or pipe, connected at one end to the `ambient air (generally through an air lter) and at its other end to at least one cylinder of an internal combustion engine, so that the downstream or trailing edge of the blade is directed towards the cylinder, the intake of air resulting from theV suction of the cylinder brings about in the Vconduit a flow which is at iirst laminar and, starting from the cavity, is turbulent, which causes very tine pulverization or atomization of the carburent liquid to form a carburized mixture `having all of the desired characteristics.

Pulverization or -atomization is begun in the depressurized area, or areas, created in the portion of reduced cross-section existing in the conduit at the point of maximum thickness of the blade, viz. the neck or necks, the cavity or cutout causing the creation of a turbulent oW at this point. It is in this depressurized area o-f turbulent flow that the arrival of the liquid to be atomized, viz. the carburant, a mixture of carburants, or a carburant and noncarburant liquid, takes place.

One of the characteristics of the invention is the fact that the arrival of at least one jet of carburant in a turbulent ilow of liquid takes place in a depressurized zone. Another characteristic resides in the fact that there is provided downstream of this depressurized zone of turbulent llow another turbulent zone caused by an edge of theV there takes place an even iiner atomization of the carburant in the comburant uid.

In accordance with this invention, there is provided a carburetor body which includes a' conduit having a front or upstream end adapted to be connected to an air iilter of any convenient type and a back or downstream end adapted to be connected to the inlet opening of at leastone cylinder of the internal combustion engine. The carburetor comprises at least one blade or vane positioned between the walls of the conduit/che blade having a cavity,v or cutout, and at least one groove adapted to be connected to at least one tank of carburant, the groove opening into the cavity or cutout which is formed in the blade. A `A vaning element or shutter may also be posi-V degrees.

of maximum thickness and it is of substantially triangular outline, its yapex being directed toward the leading or ront edge of the blade, and vtwo grooves or`inlet channels are provided. The grooves are so arranged that a liquid disc is formed by the collision of the inrushing jets of carburant discharging into the cavity from the two grooves or channels. he two jets of carburant may consist of the same carburant, e.g. gasoline, or of two carburants, erg. gas-oil and alcohol, or of a carburant and a noncarburant liquid, such as water.

Indeed, the carburetor of this invention can be used for feeding of internal combustion engines, either ofthe Z-cycle for 4-cycle`type, in automotive vehicles, motorcycles, motor scooters, motor bicycles, autorails, racing and sports cars, airplanes, electric power generating installations, and the like, not only with gasoline, such as used in ordinary carburetors, but also with other carburants, used singly or in combination, which are cheaper and which cannot be used in conventional carburetors, 'such as gas-oil, benzol, ethyl alcohol (even if'impure and containing water) and the like. Similarly, as previously mentioned, mixtures of gasoline and water may also be handled.

The vaning element or shutter may, for example, take the form of a butterfly valve which is disposed in the conduit downstream of the apertured blade or vane, and which -is movable to close off the conduit in varying The vaning element may also be in the form of shutters disposed at the downstream end of the apertured blade or Vvane and movable in such manner that they'can close off the conduit in varying degrees. -In another embodiment, the vaning element may be formed from two elastic blades or discs supported by the downstream end of the apertured blade and adapted to be separated from each other in varying amounts by a movable cam.

There are also advantageously provided corrector or compensator shutters positionedin the mouth of the conduit to regulate or adjust the admission of comburant gas and the flow velocity of the latter in the front portion of the conduit, thus regulating the richness of the car-` burize'd mixture. By partially closing the mouth of the conduit by means of these corrector or compensator shutters, the quantity of air admitted is decreased, and consequently the richness of the mixture isincreased, which increases the airV passage velocity'in the front portion 'of the conduit by reason of the greater restriction ofthe cross-section of the space between the `corrector or compensator shutters as compared with thev inlet cross-section. This is useful, for example, in putting thev engine into operation or in sudden acceleration.

The operationof these shutters corresponds substantially to the operation of the `starter in a conventional carburetor.

Theremay also be disposed in the conduit or tube or pipe, downstream of the apertured blade at least one other blade which provides a new and more pronounced atomization'of the carburant liquid, thisV other blade, or one ofv these other blades, advantageously providing a vaning element.

It is necessary to provide at least one other blade down` be supported by at least one blade placed downstream of the lapertured blade. 'I

The apertured blade and/or the other blades mayl advantageously be formedl from a plastic material, eg.` a synthetic resin, or a metal,`such as copper, which 4 facilitates the ionization of particles, particularly particles of liquid carburant.

Reference will now be made to illustrative embodiments of the invention which are not to be construed as in any Way limiting the scope of the invention but which are to be considered merely as examples, these illustrative embodiments being shown in the accompanying drawings in which:

Fig. 1 is a plan view, partly in section of a carburetor embodying features of the present invention, the wall of the conduit being cutV away;

Fig. 2 is a cross-sectional view of the construction .of Fig. 1, as seen approximately along theline II-Il o Fig. 1;

Fig. 3 is a further cross sectional view of a portion of Fig. 1, as seen approximately along .the line III- 111;

Fig. 4 is a perspective view, partly broken away to show details of construction, of the hollowed-out blade or wing shown in Figs. 1 3;

Fig. 5 is'a longitudinal sectional view, partly in elevation, of a second embodiment of invention;

Fig. 6 is a cross-sectional view of the construction of Fig. 5, as seen approximately along 'the line VI-VI of Fig. 5;

Fig. 7 is an end elevational view of the front of the carburetor shown in Figs. 5 and- 6;

Fig. 8 is a perspective view of half of the atomizing device of the embodiment shown in Figs. 5-7, viz. the portion which VH1-VH1 of Fig. 5;

= Fig. 9 is atop plan view of a'third embodiment o-f the carburetor of the invention, `the upper wall of the conduit being removed;

Fig. 1lV is a top plan view similar to Fig. `8 of a further modied form of carburetor according to the invention; Fig. 12is a cross-sectional View taken approximately along the line XII-XII of Fig. 11; and

Fig. 13 is a sectional view showing the'manner' of connecting theV downstream end of the conduit of a carburetor constructed in accordance with the invention rsi with the intake opening of` a combustion engine.

Referring to the drawing, and more particularly to Figs. 1`to 4, the carburetor illustrated Icomprises a pipe or conduit 1 of rectangular cross-section which has a constant cross-section over the greaterpart of its length. The front or upstream end 24 of the conduit 1 is attached, by means of a flange 3, to an air iilter (not shown), or to an auxiliary pipe disposed between it andthe air filter, ywhich is generally the` case when only .one air lter is used for several carburetors. The backor ldownstream portion 4 is attached by a flange 5 to the side of the .inlet opening of the cylinder (no t shown) when one carburetor per cylinder is used, or to the suction pipe communicating with the intake orifice of the cylinder or the intake orices ofl several cylinders. Preferably the carburetor supplies not more than two cylinders.

In conduit 1 there is positioned a blade or wing. 6.of substantially symmetrical structure yhaving its upstream edge 7 directed toward the incoming air, the direction of flow of which is shown by the -arrow 8.

-In vthe lthicker portion 22a of the blade there is formed a substantially triangular cavity for recessr9, the` apex 10 of which is directed toward the front or upstream end of theblade and the portion 22a is further provided with two channels or grooves 11 which are parallel to the upstream edge l and open into the cavity` 9, one channel facing the other. In Fig. 4 a portion of blade 6 has been.

cutaway in order to show the relative, arrangement of the upper,

a carburetor of the is disposed below the section 'line cylinder of'V aninternal fastening nut '13 attached by a weld 14 to the exterior of the conduit 1. The nozzles 12 are connected to one or two constant level fuel reservoirs or tanks (not shown), one tank being used in the case of *a single carburant, and two tanks being used in the case of two carburants or a carburant and a noncarburant liquid.

The back or downstream portion of blade 6 has been Vtruncated and on the remaining surface 15 there are attached, as by rivets .16, two elastic discs or plates 17 formed from steel and yserving as how-adjusting or regulating shutters. The rivets 16 pass through apertures 16a. Plates 17 are separated by variable amounts by means of a cam 18 to regulate or adjust flow through the conduit. The position of maximum tlow is shown in Fig. 2 in full lines and the closed position is shown in broken lines.

From Fig. 1 it will be seen Vthat blade y6 extends entirely between the walls of the conduit, its lateral sides L19 coming into Contact with the lateral walls 20 of the conduit I1.

The carburetor shown in Figs. 1 to 4, operates as follows:

The suction of the cylinder or cylinders of the engine which is 'connected to the downstream end 4 of conduit 1 causes the inow, through the air filter,.of air into conduit 1 in the direction indicated by the arrow 8. `Up to the point -10 of blade 6, the flow of air is laminar on the i extrados and intrados of the-blade 6. Due to the p-resl ence of thecavity or cutout 9, the laminar flow is progressiwely transformed into .a turbulent ow, the line of separation between these two flows being toa great extent deined by the lateral elongated edges 21 of the triangular cavity 9, on the extrados as well as on the intrados..1L Moreover, at the height ofthe areas 22, to a great extent corresponding to the narrowed portions or necks of the flow of airinto the conduit 1, a depressurized area is produced. This phenomenon is well-known in convergent-divergent nozzles in which the flow velocity attains its maximum at the neck in creating a depression.

It is in this substantially triangular depressurized area in which there exists a turbulent flow which produces the liquid disc 23 shown in Fig. 3 at the point of contact of the two jets 24, emerging channels 11, the triangular cavity 9 being formed in the area 22a of maximum thickness in the blade. The two jets 24 may be formed from the same carburant, two different carburants, or a carburant andhoncarburant liquid suchas water. The liquid disc 23 -is transformed into tine, small drops of carburant under the combined elect of the depressurized zone and of the turbulent ow. Moreover, atomization is improved by the presence of the driving edge 30 which maintains and increases the turbulence. The small drops of liquid are thus distributed, in the direction of the arrows 25, throughout conduit 1 downstream of the blade 6' and onto plates 17. ionization of the small drops, which occurs Iby reason of passage along the downstream portion of the blade 6, particularly when the blade 6 is formed from a plastic material or a metal such as copper which insures good ionization, tends to repel lthese small liquid drops from each other (the arrows 2S diverge) and consequently assure a good distribution of the drops in the downstream portion of the conduit 1 and in the cylinder or cylinders.

As mentioned, the elastic plates 17 and the regulating cam 18 are shown in a full line in the position in which they permit maximum ilow of the carburized mixture. In the case of an auto-motive vehicle, this position of the elements 17 and 1S is produced when the driver presses the accelerator pedal to the floor. By causing the cam 18 Ito rotate about its axle 26 under the action of the accelerator pedal, the ow of the carburized mixture can be decreased to a minimum value, corresponding to the fully released position of the` acceleratorpedal, in the case of ari: automotive vehicle. This minimum value will be lzero when 'a special carburetion device is employed for reducbetween the sections 37 and 37.

ing speed, such a device being placed downstream `ofthe plates 17.

rectangular cross-section which is elongated yby a diverging pipe 32 which is secured by means ot bolts 33 which pass throughA suitable apertures in the flanges 34 and 35 of the conduit 31 and the pipe 32, respectively. The downstream end 36 of the pipe 32 is secured by means of flanges 36a formed with openings 36b (Fig. 7) to the inlet pipe'or to one of the inlet pipes of the engine, or directly to one of the intake openings of a cylinder of the engine. In the conduit 31 there are disposed, in a manner to form a prismatic converging-diverging nozzle, two winglike members 37 Aand 37. Between these members is disposed a vane or blade 38 extending entirely between the wall surfaces defined by members 37 Iand 37, the lower and upper ends of the blade being in contact with the upper surface of section 37 and the lower surface of section 37', respectively.

In the thickest portion 33 of the blade 3S there is formed a substantially triangular cavity 39, the apex 40 of which is directed toward the leading or upstream edge 41 of the blade 38. Two channels or grooves 42 are formed in blade 33 and in members 37 and 37 and these channels are adapted to be connected to one or two constant-level tanks (not shown) supplying a carburant, oarburants, or a carburant and a noncarburant liquid. Downstream of the atomizing structure, deiined by sections 37 and 37 and the blade 38, there are provided two shutters 45 for regulating i'low, each movable around its axle 46. In front of the atomizing structure there are disposed two corrector or compensator shutters 47 whichV are movable around axles `48.

follows:

The suction of the engine draws in air (through the air lter) into conduit 31 in the direction indicated by the arrow 49. The Velocity of the air in the conduit 31 'is accelerated in the region of the neck 50 which exists The blade 38 decreases further the cross-sectional area of the passage and further increases the velocity of the air which attains its maximum value in the region of the cavity 39 which is formed, as mentioned above, in the region 38' of blade or wing 38 where its thickness is the greatest. A signii`1- cant depression is thus produced when the air reaches the zone 38 of maximum thickness of the blade 38. In the region of the cavity 39 there thus exists a depressurized area of turbulent iiow in which a liquid disc (corresponding to the liquid disc 23 of the iirst embodiment described) is formed by bringing together the two jets of liquid emerging from the channels 42, this liquid disc Abeing transformed into tine small drops by reason of the Downstream of the atomizing turbulent liow` of air. structure defined by` sections 37 and 37 and the blade 3? there is obtained a highly carburized mixture in which `the air holds in suspension very line drops of the carburant.

which they provide minimum flow. As in the rst embodiment, if the minimum iiow is zero, a special device for the preparation of the carburized mixture, corresponding to the reduction in speed, is provided downstream o f the shutters 45.

The richness of the carburized mixture is regulated by means of the corrector or compensator shutters 47, which permit the variable adjustment of the inflow of air through opening 51 of Lconduit 31. By decreasing the iniiow of air, the richness of the carburized mixture is increased, and at the same time, the velocityof the ow of air is increased by reason of the reduction in the crosssection of the passage when the distance e between the extremities 52 of the two corrector or compensator shutters-47. is decreased. i

The third embodiment ofthe inventionshown in Figs. 9 and 10V is a variant of the first embodiment which has been described above and is shown in Figs. 1y to 4. The only differences betweenl these two embodiments lie in the form of theV cavity or cutout providedin the blade and in the construction of the vaning device or shutten Accordingly, allrparts other than the blade and the Ashutter haverbeen given the same reference numbers as the corresponding elements'of Figs. 1 and 2.

The blade 6' of theembodiment of Figs. 9 and 10 is of the same type as the blade 6 ofthe Vfirst embodiment except for the following two differences, viz.: the triangular cavity 9 of theblade is replaced by a rectangular cavity 9 formed in the blade 6 and the downstream p0rtion 6l' is provided with an edge 62 in this third embodiment but not in the first embodiment which is provided with the elastic plates 17.

The shutteringaction of the plates 17 is effected in the embodiment of Figs. 9 and 10,by a keeled butterfly regulating valve 63 which may occupy,- around its axle 64, all of the intermediate positions between the position yshown in full line on Fig. 10, corresponding to the maximum flow of the carburized mixture, and the position shown in broken lines, corresponding to minimum flow of the carburized mixture.

shown), in the depressurized areas 22 of turbulent flow existing in thevicinityf the rectangular cavity or cutout 9 which is formed `in the thickest portion 22a of the blade 6. The small liquid drops which are held in suspensionin the area 65, which lies between the edge 62 and the blade 6 and the leading edge 66 of the keeled butterfly valve 63, Vare divided into even ner small drops by the turbulence produced as a result of the action of the edge 66, the butterfly valve 63 thus not only func-V tioning to regulate the flow of carburized mixture but also serving to effect better atomization. cases, it increases the ionization of the small drops of liquid which have already been ionized by the blade 6.

In Figs. '1l and 12 lis shown a fourth embodiment of the invention in which the leading or upstream edge fol'- v lowing the cavity, e.g. the edge 30 shown in Figs. 1-4

which is'supported by the apertured blade 6, is provided at 7i by a second blade 72 disposed in conduit-1l (having the same construction as the conduits of the above described embodiments) downstream of the cutout blade 73.

The vaning device is identical with the one shown in Figs. 10 andll and the reference numbers of=Figs. 10 and `11 have been used to designate the keeled butterfly valve 63 movable around its axle 64 between the position shown in full lines, corresponding tothe maximum ow of carburized mixture, and the position shown in broken lines, corresponding to minimum flow of carburized mixture.

Moreover, in some The primary atomization is effected in this fourth em-j bodiment by means of the cutout blade 73 in which the triangular recess 74 extendsfrom the thickest part of the blade to the trailing or downstream end of the blade.

ducedin the cylinder or cylinders of the engine, thisl action occurring inthe depressurized areas 22 of minil mum Vcross-section.

. 8 V,This primary atomization effected by blade 73; ist insucient to providey an optimum carburized-.mixture.` rlherefore, in this embodiment there isprovide'dasseci# ondary atomization which is effected by the fiow`of the' carburizedmixture along the blade 72 and thakeeledn` butterfly valve 63 from their leading edges 71andx66-, respectively. n v

In Fig. 13 there is shown illustrated a typical' con#v nectionbetween the suction pipe 81, or the downstream 'portion 4 of the conduit 1 of Figs. 1 to 4 and 9 to 12, or the pipe 32 of the embodiment shown in Figs. 5- to 8,'. and the portion of the cylinder 82 surrounding theV com.`0 bustion chamber 89 above the piston 83. The valvek 84e is acted upon by the spring`85 which surrounds the stem- 86 and Vcloses the intake port in conventional manner'.

it should be noted that it is advantageous to dispose"l the pipe 81 in such manner that the carburized mixture, drawn in the direction of the arrow' 87,' when the pistont 83 opens the intake port, does not undergo any'signiii-, cant change yin direction as the mixturek flows'intojthe- It will be seen that the exhaust port and the conventional associated portions of the cylinder have not been shown inthe drawing.

It' will be understood that various changes may bemade in the embodiments described and illustrated, and various improvements or additions, or the replace` ment ofk certain elements by other corresponding elef` ments, may be effected without departing from the scope'f of the invention as defined in the appended claims.

For example, only one channel or more than two channels might be provided in the apertured blade to bring together the liquid or liquids in the cavity or aperture in the blade. The aperture or cavity may also be given 4 a shape `other than the triangular and rectangular shapes shown in the drawings. The device for the preparation; of the ycaiburized mixture for slew speed may also com*` Y prise an apertured blade in which at least one channel has been formed. v

A It will be further understood that, insofar as they are', not mutually incompatible, the' various features'k and details of construction of the several embodiments shown and described are interchangeable with one anothen It'is intended, therefore, that all matter containedin the foregoing description and in the drawings shall bef interpreted as illustrative only and not as limitative -of the inventinn.`

This application is a continuation-impart of my cepending application, Serial No. 377,898, filed Septem-A ber l, 1953now Patent No. 2,770,501, granted November 13, 1956.

What l claim and desireto secure by Letters Patent is:

l. A process of preparing a carburized mixture, which comprises establishing -a turbulent ilow of a combustioni supporting uid in a depressurized zone, introducing at l least two coaxial jets of liquid fuel into said depressurized zone of turbulent flow in opposite directions and -towards each other, said jets'being thereby atomized by collision` and entrained by the flow of said combustion-supportingr uid, and creating a second turbulent area downstream, of the depressurized area of turbulent flow to effect any even finer atomization of the fuel in the combustioni` supporting fluid. Y 2. A carburetor comprising, in combination, a conduit having a front end adapted to receive a current of yair andk to be .connected to` an air filter, and a back end adapted to communicate with the intake port of a cylinvder of the engine to be fed, at least one vane of aerofoil blade, said channels beingy adapted ,to communicate with at least one source of a combustible lluid, and means for regulating, theilow of fluid through said conduit'.

3. A carburetor as defined in claim 2, wherein said triangular aperture is formed yin the area of maximum thickness of the vane.

4. A carburetor as defined in claim 2, wherein the said substantially triangular aperture has its apex directed toward the leading edge of said vane.

5. A carburetor as defined in claim 2, wherein said last-named means comprises a movable butterfly valve disposed in said conduit downstream of said vane.

6. A carburetor as dened in claim 2, wherein said last-named means comprises movable shutters disposed in said conduit downstream of said vane.

7.,A carburetor as defined in claim 2, wherein movable shutters are provided n the mouth of the conduit to regulate the flow velocity of intake air in the front portion of the conduit.

8. A carburetor as defined in claim 2, wherein at least one second vane is disposed in the conduit downstream of the apertured vane.

9. `A carburetor as defined in claim 2, wherein the apertured vane is formed from plastic material, whereby to facilitate ionization of the atomized particles.

10. A carburetor as defined in claim 2, wherein the apertured vane is formed from copper.

11. A carburetor as defined in claim 2, wherein the apertured vane and the last-named means in the conduit are formed at least in part of a plastic material, whereby to facilitate the ionization of the atomized particles.

l2. A carburetor as defined in claim 2, wherein the apertured vane and the last-named means are formed at least in part of copper.

13. A carburetor as defined in claim 2, wherein there are provided in the conduit two winged sections to define a neck of narrowed cross-section in said conduit, the apertured vane being disposed in this neck.

14. A carburetor comprising, in a conduit of rectangular cross-section having an upstream end adapted to receive a current of air and a downstream end adapted to communicate with the intake part of a cylinder of the engine to be fed, an aerofoil main blade of varying thickness and of substantially symmetrical profile disposed 'between two lateral walls of said conduit, said main blade being completely traversed by an aperture of substantial dimensions relative to the dimensions of said blade, at least two channels opening into said aperture, said channels being adapted to communicate with at least one source of carburant, at least one other aerofoil blade including a leading and a trailing edge downstream of said aperture, and means for limiting the flow of uid at least downstream of said aperture.

15. A carburetor as claimed in claim 14, wherein said aperture is substantially triangular with its apex directed towards said upstream end and is formed in the area oi maximum thickness of said main blade.

16. A carburetor comprising in combination, a conduit having a front extremity adapted to receive a ow of air and to be connected to an air filter, and a rear extremity adapted to communicate with the intake port of a` cylinder of an internal combustion engine, at least one vane of aerofoil cross-section disposed. Wholly within the walls of said conduit, at least one leading edge on the upstream side of said vanes, a substantially triangular aperture formed transversely in one of said vanes, at least two channels opening into said aperture, said channels being adapted to communicate with at least one source of a combustible uid, means forv regulating the flow of fluid through said conduit, said means com prising two elastic plates supported by the downstream portion of said apertured vane and a movable cam for selectively separating said plates.

References Cited in the le of this patent UNITED STATES PATENTS 

